🔐 Security

Privacy,
built into the core

Koto is built around privacy: encryption keys stay on your devices, registration needs no phone number, and there's no profile for ad targeting.

Access key

Your account is a secret phrase

On registration Koto generates 12 words — a cryptographic key, just like in a crypto wallet. It's stored only on your device, so we have no access to your account and never share it with third parties.

  • Sign up without a phone number
  • Move to a new device with the same 12 words
  • Lose the phrase, lose access: only you hold the key
Secret phrase
12 words · on device only
1river
2cloud
3tiger
4coffee
5anchor
6pine
7wind
8marble
9lotus
10comet
11ruby
12falcon
Protection technology

What's under the hood

End-to-end encryption

Encrypted chats — messages are visible only to participants. Keys never leave your devices.

Disappearing messages

On a timer — the message vanishes for both sides.

Forward secrecy

MLS continuously rotates keys — past messages stay protected even if a device is compromised.

Blind relay

The server routes only ciphertext and never sees the contents of your conversations.

Open core

Koto's cryptographic core is open and available for independent audit.

No ad profile

We don't use the contents of your private chats for ad targeting.

Transparency

More details in the privacy policy

What we store, what we don't, and how encryption is implemented.

Download for Windows